HABITAT SELECTION AND MOVEMENT ECOLOGY OF THE CALIFORNIA POPULATION OF GREAT GRAY OWL, STRIX NEBULOSA YOSEMITENSIS | |||
Heather L Mackey; Yosemite National Park; heather_mackey@nps.gov; Ramiro Aragon Perez, Rachel V. Blakey, Sarah Stock, Dustin Garrison, Mike McDonald, Katherine Gura, Bryan Bedrosian, Rodney B. Siegel | |||
Abstract: Great gray owls (GGOWs) in the Sierra Nevada are considered a genetically unique subspecies (Strix nebulosa yosemitensis), with low genetic diversity and a small population size. The majority of this population resides in Yosemite National Park where it’s associated with meadow areas subject to short-term disturbances from park activities and is at risk of wildlife-vehicle collisions, the greatest known source of mortality. From March 2022 to March 2024, we collected movement data from five owls with GPS transmitters, and compiled habitat data at use points derived from remotely-sensed data and field-based surveys. We addressed three objectives: (1) describe diel activity and seasonal space use of GGOWs, (2) identify key habitat variables that predict foraging and roosting habitat selection, and (3) determine drivers of habitat selection along roads. We found that GGOW foraging was positively associated with canopy density but negatively associated with number of canopy layers and canopy cover. We also found that GGOW roosting was positively associated with number of canopy layers, canopy density, and canopy cover. This work will aid in the conservation of California’s GGOW population by informing meadow restoration and management of roadside vegetation within GGOW home ranges. | |||
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